Tyupkin

Tyupkin is a Windows-based malware program identified in the mid-2010s that targets Bitcoin ATMs and the wallets connected to them. It is described as a banking Trojan designed to enable unauthorized withdrawals by compromising the ATM’s control system and the associated Bitcoin wallet.

Operation and techniques: Tyupkin is typically installed on the computer that controls a Bitcoin ATM. Once active, it can interact with the wallet software and, in some variants, capture credentials or other sensitive data. A key feature involves the generation or receipt of a 20-digit code that, when entered on the ATM’s keypad within a predefined, limited time window, authorizes a withdrawal of bitcoins from the ATM’s wallet to the attacker’s wallet. The attack relies on physical access to the ATM and the operator’s interaction with the device during the allowed window, after which funds are moved without the legitimate owner’s consent.

Impact and context: The malware attracted attention from security researchers around 2015, who described Tyupkin as a notable example of how attackers could exploit Bitcoin ATM withdrawal mechanisms rather than targeting wallets directly. Incidents attributed to Tyupkin have been reported in Russia and neighboring regions, illustrating the vulnerabilities present in some Bitcoin ATM deployments when proper security controls are lacking.

Mitigation and defense: Effective defenses include keeping ATM and control software up to date, restricting network access and external ports, implementing strong authentication and access controls for ATM operators, and monitoring for unusual withdrawal patterns or offline transactions. Physical security, regular security audits, segmentation of ATM networks from public networks, and safeguarding wallet credentials are also important measures to reduce the risk of such attacks.